Spencer J. Nielson and Wendy Birmingham, Department of Psychology
Introduction
Marriage has been positively associated with better physiological health outcomes, although the specific pathways by which this occurs remains somewhat elusive. Additionally, the quality of marriage appears to influence the health benefits derived from marriage. Marital partners, like other social relations, can be sources of support and understanding but can also be sources of criticism, conflict, and jealousy. Research has shown varying degrees of both positivity and negativity co-occurring within close relationships (i.e., ambivalence) and may provide a more accurate representation of marital processes. Cardiovascular outcomes and marital quality have been linked (think “fight or flight”), and one physiological pathway between marital quality and health may be via neural pathways of the autonomic nervous system and limbic system. Our brains are set up for safety and social engagement, which operate through neural (vagal) pathways of the autonomic nervous system. Vagal pathways dampen the fight/flight response; the limbic system activates our fight/flight response and is responsible for our emotional life and memory formation. Research has shown regulated autonomic reactivity to be linked to relationship functioning such that conflictual interactions are marked by greater reactivity, whereas couples with lower reactivity have less conflictual interactions. However, no such link has been examined in ambivalent relationship quality. Thus, a main objective of this study is to gain understanding of the neurological pathways by which marriage impacts health by examining positive and negative (ambivalent) relationship quality on health outcomes.
Methods
Twelve heterosexual married couples (N=24) who were married for a minimum of two years individually completed demographic information, health information, and assessments on marital quality. Individuals were categorized via the positivity and negativity within their marriage relationship as supportive (i.e., marriage was highly positive with little negativity) or ambivalent (highly positive but also highly negative). Couples were recruited through BYU married housing and SONA. Couples participated in 2 sessions. The first session involved a audio/video-recorded conflict discussion task completed at the University Parkway Center. Twenty-four to seventy-two hours after the discussion task, couples reported to the BYU MRI Research Facility where structural and functional MRI images were obtained on each spouse. During the scans, each participant watched a spliced recording of (a) the prior conflict discussion with (b) neutral stimuli, in 30-second intervals. Following the scans, couples participated in a clinician-led positive couple task, and were debriefed.
Analysis
Demographic analysis was completed via SPSS (v.23). Mean age of participants was 27 (SD 5.9); mean length of marriage was 3.5 years (SD 2.1). Most participants were college educated (66.7% graduated college; 33% had some college) and most (67%; N=16) rated their marital relationship to be ambivalent (high positivity and high negativity). A 2×2 analysis was conducted on both ambivalent and supportive groups and the viewed conditions (discussion and neutral stimuli).
Results
We did not find significant differences between the two groups (supportive and ambivalent) across the regions. As expected, we found significant differences by condition (discussion task viewing and nature viewing; see Image 1 and Image 2) in the left hippocampus (p=0.021) (see Figure 1), in the left amygdala (p=0.05) (see Figure 2), and the right amygdala (p=0.04)(see Figure 3). Our main aim was to determine the group x condition effect, so we next examined this interaction and found significant differences in activation of the left amygdala (p=0.025) (see Figure 2) and in the right hippocampus (p=0.013) (see Figure 4) indicating differences between the discussion and nature condition across the groups. Ambivalent individuals showed significantly decreased right hippocampus activation, and supportive individuals showed significantly increased activation in the left amygdala.
Discussion
The left amygdala is associated with emotional arousal and has also been linked to social anxiety, aggression, and fear (Ziabreva, Poeggel, Schnabel, & Braun, 2003; Feinstein et al., 2013). It is interesting that our supportive couples showed greater left amygdala activation. There may be several interpretations to the findings we collected in regards to the high left amygdala reactivity of supportive couples and low reactivity of ambivalent couples. One possible interpretation of such results could be in reference to the nature of each couple’s disagreements. Individuals that view their marriages as supportive may have fewer areas of disagreement with their spouse and may participate in less controversial discussions. Thus, when these couples are engaged in such controversial discussions, they may consider it somewhat more distressing compared to individuals that rate their marriages to be ambivalent, who may find such controversy more commonplace in their marriages.
Limitations
Our participants were mostly white (23 Caucasian, 1 Hispanic/Latino), educated young people. Most of our participant had not been married long. Further research may yield differential results in a more ethnically diverse population. Further, older couples, and those who have been married longer duration may also exhibit differential responses. More research is needed to understand the specific pathways linking marital quality and neurological processes.